Narcolepsy is estimated to have a genetic link: 8 percent to 12 percent of individuals with narcolepsy have a close relative with the disease. The importance of this link, however, is not well known; between the full-fledge manifestation of the syndrome and its absence, it may exist sub-syndromes that can be associated with genetic markers of narcolepsy. The proposed research focuses on the identification of specific symptomatology patterns that will constitute the narcolepsy spectrum in narcoleptic patients and their family. All narcoleptic subjects (about 200) coming from the Narcolepsy Center of the Stanford University and their first-degree family (parents (mother and father if still alive), sibling and children 12 years or older) will be interviewed by telephone using the Sleep-EVAL system. A control group for environmental factors composed of spouses or roommates of narcoleptic subjects will also be interviewed. At the first step, the narcoleptic subjects will be contacted by telephone. The interviewer will explain the study and will ask them if they want to participate in the survey. Subjects who want further information will be send an official letter if they willing so, or they could also call one of the researcher involved in the project. Once the consent obtained, the interviewer will ask the narcoleptic subject to provide the names and telephones number of his/her father and mother, brother(s) and sister(s) and children. A blood sample (3-5 ml) will be asked also to all participants. This will allow us to link some genetic markers of narcolepsy to specific symptoms even in subjects without the full-fledge manifestation of the disease.